The present invention relates generally to the prevention of destructive conditions in gas driven systems, where the gaseous medium is toxic, or explosive, or both. More particularly, the invention relates to means for detecting the onset of system conditions which are potentially dangerous to the integrity of a gaseous system, and relieves those conditions before a rupture or other disaster to the system results.
There are several gas driven systems in both commercial and consumer use. Cooling systems, and particularly commercial refrigeration systems, are predominantly pressurized gas driven, and ammonia is the current coolant of choice for such systems. However, free ammonia is considered toxic, and when used in a refrigeration system where expansion and compression of the gaseous medium is constantly taking place, the opportunity for breach of the system, with the concurrent escape of toxic gasses, is great.
By way of example, one need only consider the stress placed on such a system when ambient temperatures are driven into high ranges, such as by explosion or fire. Pressures in the system are quickly driven upwardly, and potentially beyond the design parameters of the system itself. Depending on the gaseous medium, a rupture of the system could have calamitous results. Similar problems can result from seismic disturbances. It is such problems that the present .invention attempts to address.